Report on Etna (Italy) — December 1977
Natural Science Event Bulletin, vol. 2, no. 12 (December 1977)
Managing Editor: David Squires.
Etna (Italy) Frequent eruptions from Northeast Crater continued into January
Please cite this report as:
Global Volcanism Program, 1977. Report on Etna (Italy) (Squires, D., ed.). Natural Science Event Bulletin, 2:12. Smithsonian Institution.
37.748°N, 14.999°E; summit elev. 3320 m
All times are local (unless otherwise noted)
Frequent eruptions from Etna's Northeast Crater continued through early January (table 1). Since the 2-4 November activity, progressively briefer 1-day eruptions occurred on 7, 22, and 25 November. On 6 December, extrusion of a single lava flow began at about 1100 from a NNE-trending fissure on the N side of the Northeast Crater. The flow traveled 4.5 km down the E flank before the eruption ended at 2200. On 24 December, tephra was thrown 1,000 m above the vent, and renewed activity 5 days later, accompanied by small earthquakes felt in nearby villages, projected tephra several hundred m above the vent. Lava extrusion resumed 2 January and the flow had advanced 1 km on a 150-m-wide front by evening. The eruption was continuing as of the morning of 4 January.
|Month||Dates of Eruption|
|Nov 1977||2-4, 7-8, 22 (10 hrs), 25 (7-8 hrs), 27 (10 hrs)|
|Dec 1977||6 (8 hrs), 10-(?)13, 18, 24-25, 29|
|Jan 1978||2-3, 4, 5, 7|
|Mar 1978||25-26, 27-28|
Geologic Background. Mount Etna, towering above Catania, Sicily's second largest city, has one of the world's longest documented records of historical volcanism, dating back to 1500 BCE. Historical lava flows of basaltic composition cover much of the surface of this massive volcano, whose edifice is the highest and most voluminous in Italy. The Mongibello stratovolcano, truncated by several small calderas, was constructed during the late Pleistocene and Holocene over an older shield volcano. The most prominent morphological feature of Etna is the Valle del Bove, a 5 x 10 km horseshoe-shaped caldera open to the east. Two styles of eruptive activity typically occur, sometimes simultaneously. Persistent explosive eruptions, sometimes with minor lava emissions, take place from one or more summit craters. Flank vents, typically with higher effusion rates, are less frequently active and originate from fissures that open progressively downward from near the summit (usually accompanied by Strombolian eruptions at the upper end). Cinder cones are commonly constructed over the vents of lower-flank lava flows. Lava flows extend to the foot of the volcano on all sides and have reached the sea over a broad area on the SE flank.
Information Contacts: R. Romano and L. Villari, IIV; J. Guest, Univ. of London; New York Times; UPI.